Markup Languages: More Than HTML5 - Web Standards: Mastering HTML5, CSS3, and XML - page 82

Table 3-8. ( continued )

Attribute Element(s) Description Value

pattern input Pattern to be matched by the value

of the form control

Regular expression matching
the JavaScript pattern
production

placeholder input , textarea

Visible label placed within the
form control

Text

poster video Poster frame displayed prior to

video playback

URL

preload audio , video none | metadata | auto Buffering hint for media

readonly input , textarea

Determines whether the value is
editable

Boolean attribute

rel a , area , link Relationship between the

document containing the
hyperlink and the destination
resource

Set of space-separated tokens

required input , select , textarea Determines whether the control is

required for form submission

Boolean attribute

reversed ol List with reversed numbering Boolean attribute

rows textarea Number of lines to show Non-negative integer greater

than zero

rowspan td , th Number of rows that the cell is to

span

Non-negative integer

sandbox iframe Security rules for nested content Unordered set of unique

space-separated tokens
consisting of allow-same-
origin, allow-forms, and
allow-scripts (ASCII case-
insensitive)

spellcheck true | false HTML elements Specifies the need for spelling and

grammar check

scope th row | col | rowgroup |

colgroup

Specifies header cell scope

selected option Option selected by default Boolean attribute

shape area circle | default | poly | rect Shape type in an image map

size input , select

Control size Non-negative integer greater

than zero

sizes link Icon size for rel="icon" Unordered set of unique

space-separated tokens
(ASCII case-insensitive)

( continued )